Nicotinic acetylcholine receptor subunits in rhesus monkey retina.
OBJECTIVE
The purpose of this study was to detect and establish the cellular localizations of nicotinic acetylcholine receptor (nAChR) subunits in Rhesus monkey retina.


METHODS
Retinas were dissected from the eyes of monkeys killed after unrelated experiments. RNA was extracted and analyzed by RT-PCR, using primers designed against human sequences of alpha3-alpha7, alpha9, and beta2-beta4 nAChR subunits. The RT-PCR products were separated by gel electrophoresis and sequenced. Frozen sections of postmortem fixed monkey eyes were immunolabeled with well-characterized and specific monoclonal antibodies against the alpha3, alpha4, alpha6, alpha7, beta2, or beta4 nAChR subunits and visualized with fluorescence labeling.


RESULTS
Products of the predicted size for the alpha3-alpha7, alpha9, and beta2-beta4 nAChR subunits were detected by RT-PCR in Rhesus monkey retina. Homology between transcripts from monkey retina and human nucleotide sequences ranged from 93 to 99%. Immunohistochemical studies demonstrated that neurons in various cell layers of monkey retina expressed alpha3, alpha4, alpha7, or beta2 nAChR subunits and cells with the morphology of microglia were immunoreactive for the alpha6 or beta4 nAChR subunits.


CONCLUSIONS
nAChR subunits are expressed in the monkey retina and localize to diverse retinal neurons as well as putative microglia. Besides mediating visual processing, retinal nAChRs may influence refractive development and ocular pathologies such as neovascularization.
Liu
Ji
J
Department of Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6075, USA.
McGlinn
Alice M
AM
Fernandes
Alcides
A
Milam
Ann H
AH
Strang
Christianne E
CE
Andison
Margot E
ME
Lindstrom
Jon M
JM
Keyser
Kent T
KT
Stone
Richard A
RA
D000818:Animals; D017931:DNA Primers / Q000737:chemistry; D004591:Electrophoresis, Polyacrylamide Gel; D019084:Fluorescent Antibody Technique, Indirect; D008253:Macaca mulatta; D008856:Microscopy, Fluorescence; D021122:Protein Subunits / Q000235:genetics / Q000378:metabolism; D012333:RNA, Messenger / Q000378:metabolism; D011978:Receptors, Nicotinic / Q000235:genetics / Q000378:metabolism*; D012160:Retina / Q000378:metabolism*; D055351:Retinal Neurons / Q000378:metabolism; D020133:Reverse Transcriptase Polymerase Chain Reaction
D017931:DNA Primers; D021122:Protein Subunits; D012333:RNA, Messenger; D011978:Receptors, Nicotinic